US20020074900A1 - Ring -type piezoelectric ultrasonic motor - Google Patents
Ring -type piezoelectric ultrasonic motor Download PDFInfo
- Publication number
- US20020074900A1 US20020074900A1 US09/956,879 US95687901A US2002074900A1 US 20020074900 A1 US20020074900 A1 US 20020074900A1 US 95687901 A US95687901 A US 95687901A US 2002074900 A1 US2002074900 A1 US 2002074900A1
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- Prior art keywords
- ring
- rotor
- type
- protruding teeth
- type resonator
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- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- 239000000919 ceramic Substances 0.000 claims abstract description 12
- 239000000463 material Substances 0.000 claims description 5
- 239000004593 Epoxy Substances 0.000 claims description 2
- 239000002184 metal Substances 0.000 claims description 2
- 238000005476 soldering Methods 0.000 claims description 2
- 238000006073 displacement reaction Methods 0.000 abstract description 2
- 230000005684 electric field Effects 0.000 abstract description 2
- 238000005452 bending Methods 0.000 description 8
- 238000010586 diagram Methods 0.000 description 3
- 238000013016 damping Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
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Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02N—ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR
- H02N2/00—Electric machines in general using piezoelectric effect, electrostriction or magnetostriction
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02N—ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR
- H02N2/00—Electric machines in general using piezoelectric effect, electrostriction or magnetostriction
- H02N2/10—Electric machines in general using piezoelectric effect, electrostriction or magnetostriction producing rotary motion, e.g. rotary motors
- H02N2/16—Electric machines in general using piezoelectric effect, electrostriction or magnetostriction producing rotary motion, e.g. rotary motors using travelling waves, i.e. Rayleigh surface waves
- H02N2/163—Motors with ring stator
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02N—ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR
- H02N2/00—Electric machines in general using piezoelectric effect, electrostriction or magnetostriction
- H02N2/0005—Electric machines in general using piezoelectric effect, electrostriction or magnetostriction producing non-specific motion; Details common to machines covered by H02N2/02 - H02N2/16
- H02N2/005—Mechanical details, e.g. housings
- H02N2/0065—Friction interface
Definitions
- the present invention relates to a ring-type piezoelectric ultrasonic motor which is different from the Electro-magnetically driven conventional motors and that has applications in robotics, precise controlling xy stage for semiconductor fabrication and optics, and automation equipments. More specifically, the present invention relates to a ring-type piezoelectric ultrasonic motor that is driven by a frictional force between rotor and stator, and stator is produced a mechanical displacement by a piezoelectric ceramics applying an alternate electric field with an ultrasonic frequency (above 16 kHz).
- the driving methods generally known for piezoelectric ultrasonic motors are operating either through a half-wave batch converter or a quarter-wave batch or several quarter-wave batch converters for the operating shaft with a smaller cross section.
- the basic principle of an ultrasonic drive is using a ring-type stator for bending vibration.
- piezoelectric ceramics that generate a mechanical vibration in order to allow their progression in the form of a wave, are attached and at the other face, protruding teeth that transmit an ellipsoidal phase change to the driving shaft on the pressure between the stator and the rotor are formed.
- One object of the invention is to provide a ring-type piezoelectric ultrasonic motor which increases the rotational force by magnifying the magnitude of the vibration of concentrically protruding teeth attached to a ring type resonator.
- Another object is to provide a ring-type piezoelectric ultrasonic motor which magnifies the magnitude of the vibration of concentrically protruding teeth and the vibration speed of a ring-type resonator (a stator) that is in contact with a rotor, and which can effectively apply a compressive force between a stator and a rotor.
- FIG. 1 illustrates the essential elements the ring-type piezoelectric ultrasonic motor according to the present invention.
- FIG. 2 is a detailed diagram of the force affecting the protruding teeth and the rotor in FIG. 1.
- FIG. 3 illustrates a detailed structure of the protruding teeth.
- FIG. 4 is a detailed diagram of the protruding teeth and the rotor when a resonance occurs.
- FIG. 5 is a detailed diagram of the protruding teeth of quarter-wave batch converter when no resonance occurs.
- FIG. 6 is a cross section view of the ring-type piezoelectric ultrasonic motor according to the present invention.
- the protruding teeth ( 5 ) on one side of the ring-type resonator 1 perform as a resonator for a bending vibration and the number of the protruding teeth ( 5 ) is determined by Equation 1.
- M is the weight of the ring-type resonator (stator) ( 1 ) and ⁇ mi is the total weight of the protruding teeth ( 5 ).
- the speed of revolution can be increased by using the vibration frequency relating to the bending vibration of the ring-type resonator ( 1 ).
- Equation 1 The weight of ring-type resonator ( 1 ) and the protruding teeth ( 5 ) are determined by Equation 1. At this time, the damping of the vibration can be prevented by the required pressure P and the work capability of the whole vibration system can be improved by securing a reliable operation of the ultrasonic motor.
- the protruding teeth ( 5 ) plays a role of a quarter-wave batch converter for a bending vibration and the number for the protruding teeth ( 5 ) should be such that the weight of the half-wave batch converter part is no less than 5 times the total weight of the protruding teeth ( 5 ).
- A ⁇ / 2 in FIG. 3, where ⁇ is the bending vibration frequency of the ring-type resonator ( 1 ).
- Equation 2 The resonant condition of the protruding teeth ( 5 ) can be represented by Equation 2.
- r is the radius of driving shaft
- c is the speed of sound
- k is the form of the vibration
- l is the length of driving shaft.
- a thin ring-type piezoelectric ceramic ( 2 ) that generates an elastic traveling wave is attached to the bottom of the stator ( 1 ) and protruding teeth ( 5 ) is formed on the top of the stator ( 1 ).
- the rotor ( 3 ) on which the thin ring-type frictional material ( 4 ) is attached is put on the protruding teeth ( 5 ) is formed on the top of the stator ( 3 ).
- the shaft ( 6 ) is inserted through the bearing ( 9 ).
- the bearing ( 9 ) is firmly supported by a cover ( 11 ) and a supporting bed ( 10 ) .
- the motor for a ultrasonic drive has a ring-type resonator ( 1 ) and a thin layer of ring-type piezoelectric ceramics ( 2 ) are attached to bottom of the ring-type resonator ( 1 ).
- the above means for attachment is either through a soldering at 80-100° C. or a hard-purpose epoxy at 90-110° C.
- the piezoelectric ceramics ( 2 ) play a role of generating an elastic traveling wave and the rotor ( 3 ) under a compressive contact with the protruding teeth ( 5 ) is covered with a thin layer of frictional material ( 4 ) by the pressure P.
- Protruding teeth ( 5 ) are formed on the upper face of the ring-type resonator ( 1 ).
- the ring-type resonator ( 1 ) and the rotor ( 3 ) is located on the same shaft.
- the bearing ( 9 ) is firmly supported by a cover ( 11 ) and a supporting bed ( 10 ) and plays a role of transmitting rotational force to the driving shaft ( 6 ).
- the plate spring ( 7 ) on the upper section of the rotor ( 3 ) is in contact with the gasket ( 8 ) and exerts a force with a fixed magnitude.
- the proper pressure between the rotor ( 3 ) and the ring-type resonator ( 1 ) should be appropriately controlled and a metal gasket ( 14 ) is inserted for this purpose between the pushing plate ( 13 ) that pushes the upper section of the bearing ( 9 ) and the upper case ( 11 ).
- FIG. 1 The operation of the resonator ( 1 ) with the configuration as described previously is in FIG. 1.
- the operation of that is to convert the pure mechanical vibration from the piezoelectric ceramic ( 2 ) into an elliptical mechanical vibration by two different phases of the piezoelectric ceramics ( 2 ).
- the protruding teeth ( 5 ) that have the distribution of bending wave act as a bracing strut for the driving of the rotor ( 3 ) and their upper face is in contact with the rotor ( 3 ) in order to rotate.
- the technical solution for the protruding teeth ( 5 ) is to act as a resonator that generates a bending vibration corresponding to the resonance frequency.
- the protruding teeth are bent over a distance above “a” as shown in FIG. 5 in order to move the protruding teeth away from the resonance point.
- the ultrasonic driving according to this invention is capable of increasing the rotational force of the rotor ( 3 ) without altering the variables of the motor, resulting in an overall improvement of the whole vibration system and a reduction in the power consumption.
- the ultrasonic motor proposed according to the present invention has the advantages of being small, light, noise-free, and low on power consumption, low speed and high torque.
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- General Electrical Machinery Utilizing Piezoelectricity, Electrostriction Or Magnetostriction (AREA)
Abstract
Description
- The present invention relates to a ring-type piezoelectric ultrasonic motor which is different from the Electro-magnetically driven conventional motors and that has applications in robotics, precise controlling xy stage for semiconductor fabrication and optics, and automation equipments. More specifically, the present invention relates to a ring-type piezoelectric ultrasonic motor that is driven by a frictional force between rotor and stator, and stator is produced a mechanical displacement by a piezoelectric ceramics applying an alternate electric field with an ultrasonic frequency (above 16 kHz).
- The driving methods generally known for piezoelectric ultrasonic motors are operating either through a half-wave batch converter or a quarter-wave batch or several quarter-wave batch converters for the operating shaft with a smaller cross section.
- As an efficient movement of the driving shaft, the energy from the longitudinal oscillation of the half-wave batch converter is converted to a rotational motion of rotor under the condition of S1/S2≧5 (S1: cross section of the converter, S2: total cross section of the shaft) condition (UK Patent GB2023965 B Ultrasonic Oscillating System 1978).
- The basic principle of an ultrasonic drive is using a ring-type stator for bending vibration. On one face of the stator, piezoelectric ceramics that generate a mechanical vibration in order to allow their progression in the form of a wave, are attached and at the other face, protruding teeth that transmit an ellipsoidal phase change to the driving shaft on the pressure between the stator and the rotor are formed.
- Due to an increase in the height of the protruding teeth for a ring-type resonator (stator), the magnitude of bending vibration is magnified and partially the rotational force of the rotor increases.
- One object of the invention is to provide a ring-type piezoelectric ultrasonic motor which increases the rotational force by magnifying the magnitude of the vibration of concentrically protruding teeth attached to a ring type resonator.
- Another object is to provide a ring-type piezoelectric ultrasonic motor which magnifies the magnitude of the vibration of concentrically protruding teeth and the vibration speed of a ring-type resonator (a stator) that is in contact with a rotor, and which can effectively apply a compressive force between a stator and a rotor.
- FIG. 1 illustrates the essential elements the ring-type piezoelectric ultrasonic motor according to the present invention.
- FIG. 2 is a detailed diagram of the force affecting the protruding teeth and the rotor in FIG. 1.
- FIG.3 illustrates a detailed structure of the protruding teeth.
- FIG. 4 is a detailed diagram of the protruding teeth and the rotor when a resonance occurs.
- FIG. 5 is a detailed diagram of the protruding teeth of quarter-wave batch converter when no resonance occurs.
- FIG. 6 is a cross section view of the ring-type piezoelectric ultrasonic motor according to the present invention.
- <Description of the numeric on the main parts of the drawings>
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- The protruding teeth (5) on one side of the ring-
type resonator 1 perform as a resonator for a bending vibration and the number of the protruding teeth (5) is determined byEquation 1. - [Equation 1]
- M≦5Σ mi
- In this case, M is the weight of the ring-type resonator (stator) (1) and Σ mi is the total weight of the protruding teeth (5).
- The speed of revolution can be increased by using the vibration frequency relating to the bending vibration of the ring-type resonator (1).
- The weight of ring-type resonator (1) and the protruding teeth (5) are determined by
Equation 1. At this time, the damping of the vibration can be prevented by the required pressure P and the work capability of the whole vibration system can be improved by securing a reliable operation of the ultrasonic motor. - The protruding teeth (5) plays a role of a quarter-wave batch converter for a bending vibration and the number for the protruding teeth (5) should be such that the weight of the half-wave batch converter part is no less than 5 times the total weight of the protruding teeth (5).
- At this instance, A=λ/2 in FIG. 3, where λ is the bending vibration frequency of the ring-type resonator (1).
- The resonant condition of the protruding teeth (5) can be represented by
Equation 2. - [Equation 2]
- f=[r·c/2π·l2]k2
- In this case, r is the radius of driving shaft, c is the speed of sound, k is the form of the vibration and l is the length of driving shaft. The piezoelectric ultrasonic motor that satisfies the above conditions has the following configuration.
- A thin ring-type piezoelectric ceramic (2) that generates an elastic traveling wave is attached to the bottom of the stator (1) and protruding teeth (5) is formed on the top of the stator (1). The rotor (3) on which the thin ring-type frictional material (4) is attached is put on the protruding teeth (5) is formed on the top of the stator (3). Along the same axle of the stator (1) and the rotor (3), the shaft (6) is inserted through the bearing (9). The bearing (9) is firmly supported by a cover (11) and a supporting bed (10) .
- If the present invention is described in more detail, the motor for a ultrasonic drive has a ring-type resonator (1) and a thin layer of ring-type piezoelectric ceramics (2) are attached to bottom of the ring-type resonator (1).
- According to this invention the above means for attachment is either through a soldering at 80-100° C. or a hard-purpose epoxy at 90-110° C.
- The piezoelectric ceramics (2) play a role of generating an elastic traveling wave and the rotor (3) under a compressive contact with the protruding teeth (5) is covered with a thin layer of frictional material (4) by the pressure P.
- Protruding teeth (5) are formed on the upper face of the ring-type resonator (1). In order to accommodate a free rotation of the bearing (9), the ring-type resonator (1) and the rotor (3) is located on the same shaft. The bearing (9) is firmly supported by a cover (11) and a supporting bed (10) and plays a role of transmitting rotational force to the driving shaft (6).
- The plate spring (7) on the upper section of the rotor (3) is in contact with the gasket (8) and exerts a force with a fixed magnitude.
- Also, the proper pressure between the rotor (3) and the ring-type resonator (1) should be appropriately controlled and a metal gasket (14) is inserted for this purpose between the pushing plate (13) that pushes the upper section of the bearing (9) and the upper case (11).
- In order to prevent the occurrence of mechanical noises and vibrations between the ring-type resonator (1) and the rotor (3), it is preferable to insert a rubber gasket (8) and the gasket acts as an acoustic insulator.
- The operation of the resonator (1) with the configuration as described previously is in FIG. 1. The operation of that is to convert the pure mechanical vibration from the piezoelectric ceramic (2) into an elliptical mechanical vibration by two different phases of the piezoelectric ceramics (2).
- The protruding teeth (5) that have the distribution of bending wave act as a bracing strut for the driving of the rotor (3) and their upper face is in contact with the rotor (3) in order to rotate. As shown in FIG. 4, during resonance the technical solution for the protruding teeth (5) is to act as a resonator that generates a bending vibration corresponding to the resonance frequency. During the no resonance, the protruding teeth are bent over a distance above “a” as shown in FIG. 5 in order to move the protruding teeth away from the resonance point.
- When the bent protruding teeth (5) makes a contact with the rotor (3), the magnitude of the vibration on the upper section of the protruding teeth (5) increases and consequently brings about a mechanical change in the rotor (3) due to mutual reactions of the friction between the upper part of the protruding teeth (5) and the rotor (3). Using the distance “a” in FIG. 4 and FIG. 5 can increase the rotating speed.
- According to the condition of the equation of M≦5Σ mi about the half-wave resonator, the needed pressure P and the mass of successive ring-type area of the ring-type resonator (1) except the protruding teeth (5), the damping of vibration doesn't happen and guarantees a reliable operation of ultrasonic motor
- As stated above, the ultrasonic driving according to this invention is capable of increasing the rotational force of the rotor (3) without altering the variables of the motor, resulting in an overall improvement of the whole vibration system and a reduction in the power consumption.
- The ultrasonic motor proposed according to the present invention has the advantages of being small, light, noise-free, and low on power consumption, low speed and high torque.
- These characteristics can compensate for the shortcomings of the conventional motors as well as having a wide application area such as semiconductor fabrication equipments, precise control driver for optical equipments, robot joint driving motors, motor driven blinders and motor driven curtains, weapon driving system
Claims (5)
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR10-2000-0077156A KR100376137B1 (en) | 2000-12-15 | 2000-12-15 | Ring-type Piezoelectric Ultrasonic Motor |
KR2000-77156 | 2000-12-15 | ||
KR77,156 | 2000-12-15 |
Publications (2)
Publication Number | Publication Date |
---|---|
US20020074900A1 true US20020074900A1 (en) | 2002-06-20 |
US6628045B2 US6628045B2 (en) | 2003-09-30 |
Family
ID=19703126
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/956,879 Expired - Fee Related US6628045B2 (en) | 2000-12-15 | 2001-09-21 | Ring-type piezoelectric ultrasonic motor |
Country Status (3)
Country | Link |
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US (1) | US6628045B2 (en) |
JP (1) | JP2002218774A (en) |
KR (1) | KR100376137B1 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040156752A1 (en) * | 2002-12-12 | 2004-08-12 | Charles Mentesana | Micro-beam friction liner and method of transferring energy |
CN107134946A (en) * | 2017-05-24 | 2017-09-05 | 宁波大学 | A kind of ultralow rotating speed travelling wave supersonic motor with curved surface stator tooth |
CN108282108A (en) * | 2018-03-27 | 2018-07-13 | 南京航空航天大学 | A kind of ultrasound electric machine precompression adjusting method and its ultrasound electric machine based on magnetic rheology elastic body |
WO2020118225A1 (en) * | 2018-12-07 | 2020-06-11 | Baker Hughes, A Ge Company, Llc | Motors for downhole tools devices and related methods |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001136761A (en) * | 1999-11-02 | 2001-05-18 | Minolta Co Ltd | Actuator |
KR101240835B1 (en) | 2011-05-19 | 2013-03-11 | 정연학 | Ultrasonic motor for driving camera lens |
Family Cites Families (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
SU817809A1 (en) | 1978-06-26 | 1981-03-30 | Специальное Проектно-Конструкторскоеи Технологическое Бюро Малых Элект-Рических Машин Производственногообъединения "Эльфа" | Rod-type ultrasonic oscillatory system |
JPS6118371A (en) * | 1984-07-03 | 1986-01-27 | Matsushita Electric Ind Co Ltd | Piezoelectric motor |
US5032753A (en) * | 1989-02-28 | 1991-07-16 | Brother Kogyo Kabushiki Kaisha | Piezoelectric transducer and an ultrasonic motor using the piezoelectric transducer |
KR910008932A (en) * | 1989-10-20 | 1991-05-31 | 야마무라 가쯔미 | Drive control device for ultrasonic stepper motor |
JPH03273878A (en) * | 1990-03-22 | 1991-12-05 | Matsushita Electric Ind Co Ltd | Supersonic motor |
JP3117817B2 (en) * | 1991-11-27 | 2000-12-18 | アスモ株式会社 | Ultrasonic motor stator and method of manufacturing the same |
FR2701340B1 (en) * | 1993-02-05 | 1995-03-24 | Imra Europe Sa | Method for producing an electrical signal distribution circuit, distribution circuit obtained and piezoelectric motor comprising such a circuit. |
JPH07293657A (en) * | 1994-04-18 | 1995-11-07 | Nippon Thompson Co Ltd | Drive device having ball screw |
US5631517A (en) * | 1994-05-23 | 1997-05-20 | Hitachi, Ltd. | Ultrasonic motor and driving for the ultrasonic motor |
KR100216980B1 (en) * | 1996-12-05 | 1999-09-01 | 윤덕용 | Non-reversible optical element using optical frequency conversion |
JPH10225152A (en) * | 1997-02-12 | 1998-08-21 | Canon Inc | Torque transmission mechanism for airtight container |
WO1998043306A1 (en) * | 1997-03-21 | 1998-10-01 | The Penn State Research Foundation | Ultrasonic motor |
JPH1175380A (en) * | 1997-08-29 | 1999-03-16 | Matsushita Electric Ind Co Ltd | Ultrasonic motor and piezoelectric vibrator using the motor |
JP3441938B2 (en) * | 1997-10-14 | 2003-09-02 | 安藤電気株式会社 | Optical pulse generator |
-
2000
- 2000-12-15 KR KR10-2000-0077156A patent/KR100376137B1/en active IP Right Grant
-
2001
- 2001-09-21 US US09/956,879 patent/US6628045B2/en not_active Expired - Fee Related
- 2001-12-05 JP JP2001371878A patent/JP2002218774A/en active Pending
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040156752A1 (en) * | 2002-12-12 | 2004-08-12 | Charles Mentesana | Micro-beam friction liner and method of transferring energy |
US7245061B2 (en) * | 2002-12-12 | 2007-07-17 | Honeywell Federal Manufacturing & Technologies, Llc | Micro-beam friction liner and method of transferring energy |
CN107134946A (en) * | 2017-05-24 | 2017-09-05 | 宁波大学 | A kind of ultralow rotating speed travelling wave supersonic motor with curved surface stator tooth |
CN108282108A (en) * | 2018-03-27 | 2018-07-13 | 南京航空航天大学 | A kind of ultrasound electric machine precompression adjusting method and its ultrasound electric machine based on magnetic rheology elastic body |
WO2020118225A1 (en) * | 2018-12-07 | 2020-06-11 | Baker Hughes, A Ge Company, Llc | Motors for downhole tools devices and related methods |
GB2594405A (en) * | 2018-12-07 | 2021-10-27 | Baker Hughes Holdings Llc | Motors for downhole tools devices and related methods |
US11193354B2 (en) | 2018-12-07 | 2021-12-07 | Baker Hughes Holdings Llc | Motors for downhole tools devices and related methods |
GB2594405B (en) * | 2018-12-07 | 2022-08-03 | Baker Hughes Holdings Llc | Motors for downhole tools devices and related methods |
Also Published As
Publication number | Publication date |
---|---|
JP2002218774A (en) | 2002-08-02 |
KR20020046817A (en) | 2002-06-21 |
US6628045B2 (en) | 2003-09-30 |
KR100376137B1 (en) | 2003-03-15 |
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